Covers for component surfaces, which are primarily used as protection during welding tasks where splashes are generated are well known. Such covers range from provisional solutions in the form of aluminum foil attached with aluminum adhesive tape to more elaborate solutions in the form of complex steel structures which are connected by means of screws to the components to be protected.
It is often the case that the surfaces of components near welding connections are already fine-machined or finished. If welding splashes hit such surfaces, then they can partially melt the component and they remain adhered to it. Removal of such cooled down components can be very labor-intensive, for example requiring removal by turning on the lathe, by milling or by grinding. Often, nicks, margins, bumps etc. remain which at least visually/aesthetically have a negative effect on the component, with the possible metallurgical effects being still more serious. The considerable local heat supply caused by a high-temperature weld splash of sizeable mass can lead to changes in the microstructure which negatively affect strength or fatigue strength, such as e.g. localized grain coarsening, embrittlement, hardening, softening, shrinkage-cavitation forming, cracking etc. By way of crack generation and crack growth, such flaws can eventually lead to failure of the component as a result of deformation or fracture. All kinds of surface coatings can also be locally damaged or destroyed by welding splashes. Therefore in many cases there is a requirement for providing a cover which safely prevents any welding splashes from contacting component surfaces.
Depending on the welding process employed, the energy content of welding splashes differs according to mass, temperature and speed, with rotary friction welding generating particularly harmful splashes as a result of its kinematics and energy density.
However, hot metal splashes occur not only during welding. Uncontrolled release of metal splashes can occur during production wherever a locally molten component material is generated with a high energy supply which is not always precisely controllable or where such splashes in a molten or liquid state can hit the surfaces of components or devices at considerable speed. Autogenous cutting as well as working with high-energy laser sources for the purpose of cutting, drilling and removing, are examples of such problematic process methods. Similarly, in the case of very substantial material removal, rotating grinding wheels or cutting-off wheels can generate critical metal splashes. All this confirms the requirement for protective covers for component surfaces.